James Webb: Supertelescope captures images of star factory

This is another spectacular image from the new James Webb Space Super Telescope.

The image shows NGC 346, a region about 200,000 light-years from Earth where many stars are being created.

Webb’s near-infrared camera captures the knots, arcs and filaments of gas and dust that are fueling this stellar nursery.

NGC 346 is embedded in a satellite galaxy of our own galaxy, the Milky Way, called the Small Magellanic Cloud — and is used as a laboratory for studying star formation processes.

The conglomerate contains relatively low concentrations of elements heavier than hydrogen and helium.

In this way, the conditions reproduce, to some extent, those that existed much earlier in the history of the Universe, when star birth was at its peak – a period known as the “Cosmic Dawn”, about three billion years after the Big Bang.

Previous space telescopes were able to detect the larger objects present in this scene, but Webb, with its superior sensitivity and resolution, allows astronomers to identify the smaller sources.

“For the first time, we can see the complete sequence of star formation in another galaxy,” says Olivia Jones of the UK Astronomy Technology Center (UK ATC) in Edinburgh, Scotland.

“Before, with Spitzer, which was one of the great observatories of the American space agency Nasa, we could detect the most massive protostars, with about five to eight times the mass of our Sun.”

“But with Webb, we have the sensitivity limits to get down to 1/10 the mass of the Sun. So, we have the sensitivity to detect very low mass stars in the process of formation, but with the resolution to also see how they affect the environment. And as you can see from the image, it’s a very dynamic environment.”

There is gas being energized in this image at temperatures of 10,000°C. Webb, on the other hand, also detects cold gas at -200 °C.

Astronomers refer to “metals” when discussing all elements heavier than hydrogen and helium. It is the material needed to make planets.

One of the big questions, therefore, revolved around whether low metallicity environments, such as NGC 346, have enough dusty material to carry out the accretion process (accumulation of matter on the surface of a star through the action of gravity) and build rocky worlds.

Webb’s observations of the conglomerate indicate that it certainly has that potential. Even the smallest protostars detected in the image have disks of dust around them.

And, by the way, this suggested planetary formation would also have been possible at the beginning of the Universe, in the Cosmic Aurora, as explained by Margaret Meixner, an astronomer at the University Space Research Association in Maryland, USA.

“The metallicity in the Small Magellanic Cloud is comparable to the peak time of star formation in the Universe. That’s when we’re basically producing most of the stars in the Universe. And that’s very interesting because it means you could potentially be forming planets around a large amount of stars”, says the researcher.

The new image of NGC 346 captured by Webb was released at the 241st meeting of the American Astronomical Society in Seattle, USA.

It was also announced that the telescope discovered its first exoplanet — the name given to planets orbiting other stars.

Formally named LHS 475 b, the planet is almost exactly the same size as our own, measuring 99% of Earth’s diameter.

Its existence had been suggested by data from NASA’s Transiting Exoplanet Survey Satellite, but Webb was able to quickly dispel doubts.

He observed the light coming from the parent star and was able to detect the drop in emission when the planet passed in front of it, something that happens every two days.

Such a short orbital period means that LHS 475 b is extremely close to its star and, as a result, is a few hundred degrees hotter than Earth.

Astronomers are trying to determine the composition of a possible atmosphere. It is possible, however, that the planet does not have one.

“This planet could very well be an airless body that has lost whatever atmosphere it once had,” says Jacob Lustig-Yaeger of the Applied Physics Laboratory at Johns Hopkins University, also in Maryland.

But Webb’s data might also be consistent with a thick carbon dioxide atmosphere with high-altitude clouds — not unlike Venus.

A paper detailing NGC 346 has been submitted to an academic journal for publication. It is currently available on the arXiv open access article repository.

This text was published here.